<!DOCTYPE html>
<html>
<body>
    <button type="button" onclick="htmlTest()">Click Me!</button>
    <p id="demo"></p>
    <p id="webDemo"></p>
</body>
<script>
function htmlTest() {
 document.getElementById('webDemo').innerHTML = 'webDemo test';
    console.log('click me input webDemo test ');
}
</script>
</html>